This project comprises several studies focused on pathological dissociation in children, adolescents, and adults. Prior findings include: electrophysiological, cognitive, and memory differences across the altered personality states of multiple personality disorder (MPD) patients; development of reliable and valid measures of dissociation in adults and children; and the induction of dissociative-like memory disturbances in normal volunteers with triazolam. Current studies include development of a meta-analysis/structural equation model of the causal relationships among trauma, dissociation, and hypnotizability; and the development of a reliable and valid adolescent self-report measure of pathological dissociation. Recent findings include the use of taxometric statistical techniques to demonstrate the typological nature of pathological dissociation; analysis of age and gender effects on dissociative symptoms in children and adolescents; and the demonstration that dissociativity and hypnotizability are different processes. This project, which was formerly Z01 MH 02367-07 LDP, has been transferred from LDP to BPB, NIMH.